For security reasons, if an application goes into full-screen mode, a warning banner is displayed:

    Press ESC to exit full-screen mode.

The JavaFX runtime will always exit from full-screen mode when the ESC key is pressed.

For some applications, the warning is not desirable, since it can cover up part of the application. In other use cases, a kiosk for example, an app might want to disable the ability to exit full-screen mode.

We could add a new property on Stage, only settable to trusted apps (it would throw a SecurityException if set by untrusted apps), something like:

Stage:
public void setFullScreenMode(FullScreenMode mode)

FullScreenMode:
public enum FullScreenMode { WARN /* default */, NO_WARN, NO_EXIT_ON_ESC }

with better names than that.